An integrated circuit device includes a substrate, a voltage monitor circuit formed on the substrate, and a trimming circuit formed on the substrate that includes a successive approximation register circuit having an input coupled to an output of the voltage monitor circuit; a beta multiplier circuit having an input coupled to an output of the successive approximation register circuit, an output coupled to a first input of the voltage monitor circuit, and a variable resistance circuit. A resistance value of the variable resistance circuit is controlled by the output of the successive approximation register.